Drill sharpener



Nov. 17, 1931. E. CROFT DRILL SHARPENER Filed Dec. 31. 1928' 5Sheets-Sheet. l

liliH LORENZO E. CkoF-r Nov. 17, 1931. L. E. CROFT DRILL SHARPENER FiledDec. 31. 1928 5 Sheets-Sheet 2 gwwzntz Zeke/v20 f. Ckorr' Nov. 17, 1931.L. E. CROFT DRILL SHARPENER Filed Dec. 31.. 1928 5 Sheets-Sheet 3 amnionv (0950 20 4 (korr Nov. 17, 1931.

L. E. CROFT 1,832,187

DRILL SHARPENER Filed D60. 31. 1928 5 Sheets-Sheet 4 gwwmtot PatentedNov. 17; 1931 STATES PATENT orrics,

LORENZO E. CROFT, OF DENVER, COLORADO, ASSIGNOR TO GARDNER-DENVERCOMPANY,

OF DENVER, COLORADO, A CORPORATION OF DELAWARE DRILL SHARPENERApplication filed December 31, 1928. Serial No. 329,563.

The present invention relates more particularly to drill sharpeners ofthe type in which difierentpressures may be brought upon the die membersfor forgingor holding purposes, the object being to provide a moreefiective connecting means between the pistons and movable die member soas to prevent canting or cocking of the movable parts.

In the accompanying drawings:

Figure 1 is a vertical sectional view through one embodiment of theinvention.

Figure 2 is a vertical sectional view on the line 22 of Figure 1.

Figures 3 and 4 are horizontal sectional views respectively on the lines3-3 and 4 4 of Figure 2. s

Figure 5 is a detail vertical sectional View somewhat diagrammatic inits character, to show more clearly the distribution and control of themotive fluid.

Figure 6 is a vertical sectional view of a modified form ofconstruction.

In theembodiment disclosed a base is employed, consisting of a lowersection 8 having a chamber 9 that constitutes areservoir for motivefluid. It is supplied from any suitable source by a pipe 10 connected toa nipple 11 formed on one side of the section 8. A vent cock 12 may beprovided on one side of the section, and a clean-out opening 13 formedin the bottom of said section is normally closed by a cap plate 14. Inthe upper portion of the section 8 is formed a vertical piston chamber15 having a bottom wall 16 that constitutes a partition between saidpiston chamber 15 and the motive fluid reservoir 9. This bottom16 hasaicentrally disposedv vertical cylinder 17 that depends into thereservoir 9 and is of considerably less cross sectional area than thesame and than the chamber 15. The top of the piston chamber 15 opensthrough the top of the section 8.

Surmounting the section 8 is another section 18 having a bottom wall 19that constitutes a head for the piston chamber 15.

This section 18 is also provided above said head 19 with a verticalpiston chamber 20 and the bottom 19 has a centrally disposed upstandingtubular guideway 21 extending intosaid piston chamber 20.'

A head plate 22 is located on the section 18 and constitutes a closurefor the upper end of the piston chamber .20. This head-plate and thesections 8 and 18 are secured together by side bolts 23 passing throughvertical ribs 2 1 in said sections and engaged with the margins of thehead plate 22.

' Formed on the head pate 22 is an upstanding' block 25 whichconstitutes amounting,

support or holder for metal working or hold- In the piston chambers and20 are reciprocatory pistons 29' and 30. Through diametrically. oppositeportions of said pistons 29 are formed vertical openings 31. The upperface of the lower piston .29 is provided with sockets '32surrounding theopenings 31.

The upper piston 30is provided with corre sponding sockets 33 in itsupper and lower sides. The upper movable head block 27 has openings 34aligned with the openings 30 and sides. I

Vertical piston rods in the form of bolts 36 pass through the openings31 and 3 1, the

31, and is provided with sockets in itslower 'heads 37 being preferablylocated against the under side of the lower piston 29 and nuts 38 beinglocated on the upper ends and bearing against the upper-head block 27. Apair of spacing sleeves 39 are located on the piston rods or bolts36-and are interposed between the pistons29 and 30. :The ends of thesesleeves fit-in the sockets 32, and 33 and said sleeves and piston-rodspass through bearing openings so formed in the head 19. The sleeves maybe provided with suitable packing rings 41. The pistons are thussheld infixed spaced relation. Interposed between the upper piston 30 and themovable head block 27 are corresponding spacing sleeves 42 whose endsare fitted into the sockets 35 of the piston 30 and the sockets 35 ofthe head block 27.

With this structure, it will be evident that the pistons are connectedin fixed relation and that both are in turn fixedly connected to thehead block 27. Moreover this connection is such that no canting orcocking of the parts can take place.

In the lower vertical cylinder 17 is a piston 43 having a flange 44 onits upper end that bears against the bottom of the piston 29. Saidpiston is provided in its lower side with a central socket 45.

Located upon one side of the base section 18 is a valve casing 47provided with a cylindrical open ended valve chamber 48. A supplypassageway 49 leads from the reservoir chamber 9 in the base section 8upwardly.

through said base section and the surmounting section 18 and opens intoan annular groove 50 formed in the chamber 48. one side of said groove50 is another groove 51, also formed in the chamber 48, and beyond thegroove 50 is a second groove 52. From the groove 51 a passageway 53leads to the upper end of the piston chamber 20. From the grooves 52 apassageway 54 leads to the upper end of the piston chamber 15. From thegroove 52 a passageway 55 leads to the dollying hammer 56 whichcooperates in'a well-known manner with the clamping dies and hammersupon a tool held thereby. The passageway 55 is controlled by a valve 56in said passageway and seating on a valve seat 57 The valve is urged toits seating position by a spring 58 and has a stem 59 projecting fromone end of the valve casing 47 In the valve chamber 48 is areciprocatory plunger valve, comprising terminal heads 60 and 61connected by a reduced portion 62. This valve has at one end a linkconnection 63 with an operating lever 64 fulcrumed at 65 on an extension66 of the valve casing 47.

When the valve is in a position, so that the head 60 is. interposedbetween the grooves 50 and 51, motive fluid supplied to the chamber 9,will be cut off from the passageways 53 and 54 and 55. Motive fluid inthe chamber 9, however, is sufficient to operate on the piston 43 andelevate the same so as to raise both pistons 29 and 30 as well as diehead 27. The die members are thus open so that a tool may be introducedbetween them. It now the valve actuatinglever 64 is moved inwardly,

ti 1 60 '11 b co 1 )ondin 1 moved 16 heat W1 6 lresl g y 'thecombination with a base section on which and the passageway 53 firstbrought into communication with the passageway 49. As a consequencemotive fluid will flow into the upper piston chamber 20 above the piston30 and move both pistons and movable die member downwardly because thearea of the piston 30 is so much greaterthan the area of the opposingpiston 43, By reciprocating the valve to admit air to said passageways53 and then cut it off and open the passageway to atmosphere through theopen end 67 of the valve chamber 48, a swaging action may be obtained.If additional holding power is desired the valve is then moved so as toopen the passageway 54 to communication with the passageway 49, as shownin Figure 5, whereupon motive fluid will operate against both pistons 20and 30 and hold the upper die head with great power. Upon a stillfurther movement of the valve lever 64 it will strike the projecting endof the valve stem 59, thereby opening the valve 56 and allowing themotive fluid to flow to the dollying hammer.

In the modification shown in Figure 6 it will be noted that the socketsare done away with in the lower and upper pistons designatedrespectively 29a and 30a and that the sleeves 39a and 42a abut the facesof said pistons. Preferably however, the sleeves have the intermediateportions of their bores enlarged as indicated at 33a while the pistonrods 36a have corresponding portions reduced as shown at 34a. The endportions of the sleeves have a snug fit with the piston rods, however,so that said sleeves are thereby effectively maintained in properrelation.

From the foregoing, it is thought that the construction, operation andmany advantages of the herein described invention will be apparent tothose skilled in the art without further description and it will beunderstood that various changes in the size, shape, propoi tion andminor details of construction may be resorted to without departing fromthe spirit or sacrificing any of the advantages of the invention.

hat I claim, is:

1. In apparatus of the character set forth, the combination with a basehaving a plurality of piston chambers in tandem, of a die member on thebase, a second and movable die member coacting with the first member,

pistons in the piston chambers, spaced piston rods passing through thepistons and eonnected to the movable die member, said pistons and themember having sockets in their opposing faces around the piston rods,spacing sleeves on the pi ston rods between the plstons and between theupper piston and the die member, said sleeves having their ends seatedin the sockets, and means for supplying and governing the supply ofmotive fluid to the piston chambers.

2. .[n apparatus of thecharacter set forth,

the apparatus is supported and having a piston chamber having a bottomhead and an member over the fixed die member, pistons in the pistonchambers, and spaced piston rods connecting the pistons together andconnecting the pistons to the movable die member. s

3. In apparatus of the character set forth,

a piston chamber provided with a bottom Wall that constitutes a head forthe upper open end of the first piston chamber, said second pistonchamber having an open upper end, a head section detachably fitted 0nthe upper end of the second section and constituting an upper head forthe open upper end of the second piston chamber, said head con stitutinga fixed die member, a movable die member over the fixed die member,pistons in the piston chambers, spaced piston rods connecting thepistons together and connecting the pistons to the movable die member,and a piston in the small depending piston chamber, the last namedpiston being operated on by the fluid in the reservoir and operatingagainst the lowermost piston.

In testimony whereof, I 'aflix my signature.

LORENZO E. CROFT.

